Sorry I meant to add this to last post.

[Stove]

I think the charge level is less important than the amp load the battery will take compared to its original CCA rating. Most of the batteries in my vehicle have lasted 5 or more years before dying. If your cars battery is still holding a charge, that's a good thing. A three year old battery isn't a concern. I'd be bothered more by a battery that was dead after 3 years.